Radiation sensitive paper security validation apparatus



July 22, 1969 J. E. BAYHA 3,457,421

RADIATION SENSITIVE PAPER SECURITY VALIDATION APPARATUS Filed Feb. 24,1966 5 Sheets-Sheet 1 RELAY CIRCUIT 7 4O 42 NSING 9O CIRCUIT 77 ACCEPTOR FIG. I

INVENTOR.

ATTORNEYS JACK E. BAYHA J. E. BAYHA July 22, 1969 RADIATION SENSITIVEPAPER SECURITY VALIDATION APPARATUS Filed Feb. 24. 1966 3 sheetsfsheet 2FIG.

THE UNITED STATES OFAMERICA 7 Y FIG. 6

INVENTOR.

JACK E. BAYHA ATTORNEYS :05 IO? v sa a;

July 22, 1969 J. E. BAYHA 3,457,421

RADIATION SENSITIVE PAPER SECURITY VALIDATION APPARATUS Filed Feb. 24,1966 3 Sheets-Sheet 3 2 PHOTOCELL PREAMPLIFIER -D.C.RESTORER SHAPERPUP-FLOP pupp ACTUATE REMAINDER No '5 SWITCH OF SENSING cmcun' 79AREJECTVALIDATE FIG. 7

LIGHT LIGHT 60- DARK 'PHOTOCOPY COUNTERFEIT T 50 BILL 4 DARK GENUINEBILL TlME INVENTOR.

A Y Fla 8 BY, J CK E BA HA ATTORNEYS United States Patent m 3,457,421RADIATION SENSITIVE PAPER SECURITY VALIDATION APPARATUS Jack E. Bayha,Chesterland, Ohio, assignor to Transmarine Corporation, Chesterland,Ohio, a corporation of Ohio Filed Feb. 24, 1966, Ser. No. 529,750 Int.Cl. G01n 21/32, 21/30; H011 39/12 US. Cl. 250-219 Claims ABSTRACT OF THEDISCLOSURE An apparatus for authentication of paper securities, and moreparticularly, a device for receiving and identifying as genuine a pieceof paper money by measuring the parallel printed lines behind theportrait in the paper money. This is accomplished by utilizing a reticlewith a lined pattern similar to the pattern in the portrait background,moving the reticle and/ or the paper money relative to each other Whilesimultaneously passing radiated energy through the bill and the reticlefor detection by a suitable photocell or other detector. The relativemovement between the reticle and portrait background of the bill causesalignment and misalignment of the lines enabling an accurate measurementto be made of the density of the ink which makes up the lines in theportrait background of the paper money. This measurement must exceed apredetermined minimum, and must exceed this minimum for a predeterminedminimum number of times during the relative movement between the reticleand/ or the paper money before a validation signal is achieved. Thevalidation signal may be followed by the performance of a vendingfunction.

This invention relates to an apparatus for authentication of papersecurities, and more particularly, to an apparatus for receiving andidentifying as genuine a piece of paper money by measuring the parallelprinted lines behind the portrait in the paper money, which may befollowed by the performance of a vending function.

This application represents a validation technique which might be usedalone or in combination with the validation circuit design of patentapplication Ser. No. 405,666, filed Oct. 22, 1964 by James K. Phares,now Patent No. 3,360,653 and also assigned to the TransmarineCorporation.

It is well known that there have been many and varied types of papersecurity validating circuits and apparatus, and that it is becomingincreasingly necessary to perform more than one validation of the papersecurity by more than one test means to obtain valid test results.Heretofore, it has not been possible to perform more than one validationtest without incurring considerable extra expense in the equipment, andfurther there has not been a technique to insure two positive, yet verysimple and foolproof validations tests in the same apparatus.

Therefore, it is the general object of the present invention to disclosea new validating technique and apparatus for performing same which mightbe used alone or in combination with the light passage validationtechnique defined in the above-identified patent application.

A further object of the invention is to provide a validation techniquefor paper securities which effectively measures the spacing and clarityof the printed lines behind the portrait in a paper security todetermine whether they meet predetermined standards.

Of specific value to this method of authentication is the inability ofknown available methods of photocopying to achieve sufiicient resolutionin attempted copying of genuine bills to generate this signal. Further,analysis of 3,457,421 Patented July 22, 1969 bogus or counterfeit billsindicates the relative relationships of light to dark signals comparedwith those of genuine currency give wide variations which can bemeasured to determine genuineness. I

The aforesaid objects of the invention and other objects, which willbecome apparent as the description proceeds, are achieved by providingin an apparatus for anthentication of paper securities having parallelequally spaced straight lines on some portion thereof, the combinationof frame means defining a testing area, means slidably received by theframe means to receive and hold a security to be validated in asubstantially flat position, the means being manually slidable into thetesting area, reticle means positioned in the testing area so as to bein substantially parallel close spaced relation to the portion of thesecurity having the parallel lines when the security is moved into thetesting area, the reticle further having straight equally spacedparallel lines of a number per inch substantially equal to the parallellines on the security to thereby create a light dark effect when thesecurity is moved into the testing area, means to pass light through theportion of the security with the parallel lines from the side thereofopposite the reticle, photocell means to view only a small selectedportion of the reticle to determine the amount of light passed throughthe security and the reticle, and circuit means to count the number oflight-dark signals created by the reticle in combination with thesecurity, upon the movement of the security a predetermined distancerelative to the reticle, and to provide a validation signal if theproper minimum number of light dark signals are counted.

For a better understanding of the invention reference should be had tothe accompanying drawings wherein:

FIGURE 1 is a digrammatic view partially in section showing theapparatus and control circuits of the invention;

FIGURE 2 is an enlarged perspective view, partially broken away, showingthe tray and arrangement of the reticle of FIGURE 1;

FIGURE 3 is a vertical cross sectional view of the reticle positiontaken on line 33 of FIGURE 2;

FIGURE 4 is a horizontal cross sectional view, as taken on line 4-4 ofFIGURE 3, through the tube mounting the reticle showing the maskingthereof;

FIGURE 5 is a plan schematic view of a one dollar bill of United Statescurrency illustrating those areas in the background of the portraitwhich are viewed by the apparatus of the invention for validation;

FIGURES 6a and 6b illustrate how a reticle with lines per inchsubstantially equal to the lines per inch in the background of theportrait will produce a detectable lightdark effect as the reticle ismoved very small distances over the surface of the bill; I

FIGURE 60 illustrates an improper light-dark eifec on the bill becauseits portrait background is not genuine;

FIGURE 7 is a block diagram showing how the signal received by thephotocell pickup associated with the reticle is passed through logic orcounting circuitry to provide a validation signal; and

FIGURE 8 is a graphic illustration of the difference in light-darksignal achieved by the apparatus of the invention for genuine,counterfeit, and photocopy bills.

The term paper money has been largely used heretofore in reference tothe article or articles to be identified by the testing apparatus ofthis invention, but this term is intended to include paper currency ofall sizes, denominations, and countries of origin, in addition to bonds,documents, other paper, textile, or colored articles which might besubject to tests for genuineness, weave, composition, color, pattern, orthe like by equipment of the character hereinafter described andclaimed. However, the apparatus of the invention is primarily designedfor the determination of genuineness of United States paper money inlower denominations. For example, one dollar, five dollar and ten dollarbills. It is designed particularly for authentication of any documentwhich has very closely equally spaced parallel lines on some portionthereof, which generally fall in the background of a portrait on thepaper security. In order to shorten the designation of the article beingtested, as called for hereinafter, it will 'be designated in thedrawings as a bill and will be so described in the specification.

-With reference to the form of the invention illustrated in FIGURE 1 ofthe drawings, the numeral indicates a bill changing apparatus supportedby a packaging frame 11 only a portion of which is indicated in thedrawing. A substantially horizontal guide rail 14, secured to the frame11, guides a bill slide 12 to an in and out position. To provideclearance for the movable bill slide 12, the dimension of the slide inthe direction normal to its slightly less than the height of the guiderail 14. The guide rail 14 is formed with a longitudinally extendinggroove 18 to slidably receive the slide 12. The slide 12 contains a billchamber 20 adapted to receive a bill 22. The bill chamber is formed by abill support plate 24 and a bill cover 26 which has an outwardlyextending lip 28 that serves as a handle for the operator. The coverplate 26 has a forwardly extending car 30 which receives a pivot pin 32to mount the cover plate '26 on the slide 12. When the cover plate 26 isopened, the lower surface of the ear 30 functions-to position the billaccurately in the bill chamber 20.

The support and cover plates have a plurality of spaced concentric bores34 which extend through the plates in a direction normal to the movementof the slide. The large number of the bores 34 provides the apparatuswith inherent versatility since a large number of different portions ofthe bill can be comparatively tested to determine the authenticitythereof.

As shown in FIGURE 1, the slide 12 is in the in position. In thisposition, the bores -34 are in alignment with matching bores 36 in aplate 38. Plate 38 is secured to and spans the lower portion of theguide rail 14. A circuit board 40 positions a selected number of lightsensitive photocells 42, such as photo diodes or photo resistors, in thebores 36. The number of cells, the electrical characteristics of theseparate cells, and the relative locations can be varied in accordancewith the unique requirements of the document being tested. Light from asuitable bulb 37 is directed through the bores and through the bill tobe detected by photocells 42.

The validation test comprising the object of the invention is achievedby mounting a testing device indicated generally by numeral 41 to theframe 11 by suitable fa'stenings 43. The device 41 has a viewing tube 45extending downwardly so as to be in closely spaced adjacent relationshipto the top surface of the bill 22. The cover plate 26 has a pair ofslots 47 and 49 cut therein, as seen in FIGURE 2, of sufficient width toallow the tube 45 to easily pass therein so the end of the tube will beover a selected portion of the bill to be tested. One or two slots areprovided, two when it is desired that two testing devices 41 might beutilized, or that the user of the apparatus will not know which side thebill will be tested. A Wedge 45a is connected to the tube 45 to preventthe end of the tube from catching on the edge of a bill as the tray 12is moved into position. The tube 45 is designed to pass over thebackground of the portrait sec tion of a United States bill. Forexample, it will pass in the areas indicated by dotted lines 47a and 49ain FIG- URE 5 of the drawings.

The tube 45 consists of a reticle 51 mounted at the bottom end so as tobe in close spaced parallel adjacent relationship to the bill 22. It isanticipated that the reticle 51 must he within about .025 inch spacedrelation from the bill 22. The other end of the tube 45 is mounted to a4 photocell 53, as clearly shown in FIGURE 3 of the drawings. The exactspaced relationship of the reticle 51 from the photocell 53 is notimportant as long as the tube 45 acts to transmit light passed throughthe reticle to the photocell 53. In order to pass light through thebill, and through the reticle 51, a high intensity light source 55 ismounted to direct its beam, indicated by dotted lines 57, through thebill 22 for passage through the reticle 51 and detection by photocell53.

The operating principle of the invention is "based on the fact that thebackground of the portrait on United States currency is made up ofparallel equally spaced lines. For example, the background behind GeorgeWashington on a US. one dollar bill has lines per inch both in ahorizontal and vertical direction. The portrait background on a fivedollar bill has approximately 117 lines per inch in a horizontaldirection and 75 lines per inch in a vertical direction, while thebackground on a ten dollar bill has approximately 75 lines per inch in avertical direction and 75 lines per inch in a horizontal direction.Therefore, it the reticle contains parallel equally spaced lines in anumber per inch substantially equal to one or the other of the parallellines in the background of the pottrait of the US, one dollar, fivedollar, or ten dollar bills, it will create a wide light-dark effectwhen the reticle is positioned in substantial alignment with one or theother of the sets of lines and in substantially parallel close spacedrelation thereover. This is rather clearly shown in FIGURE 60 where anenlarged reticle 51a is shown to produce a dark area 59. As shown inFIGURE 6b when the reticle 51a is moved upwardly in a directionindicated by arrow 61 a light area is achieved in previously dark area59. If the reticle is masked, as indicated by numeral 51b in FIGURE 4,the view through the opening 51 will be alternating dark and lightareas.

The purpose of the invention is to be able to count the number of lightto dark signals, or in other words the number of light and dark passesas the reticle 51 is moved relative to the background portion of thebill, or vice versa. It has been found that on a US. one dollar bill orother lower denomination bills a movement of only about A inch betweenbill and reticle will give as many as nine light and dark indications.If there is any appreciable difference in the lines of the background ofthe portrait to the number of lines in the reticle, light-dark areaswill not be of sufficient width to give the desired fully light or darkareas over the opening of the mask 51b. FIGURE 60 illustrates a spottyor narrow light-dark configuration which will occur when the lines inthe portrait background are blurred or of a different count per inchthan the reticle portion 5. In this instance no validation will occur.It has been found that about a 5 to 7 percent variation in the number oflines per inch between the reticle and the lines on the bill will notproduce the desired width of light-dark areas necessary to indicatevalidation. For this reason in this form of authenticity checking a onedollar or five dollar bill could be evaluated with the same reticle.

In order to indicate validation with the light-dark effect as describedabove, the reticle is masked a specific viewmg area, this most clearlyindicated in FIGURE 4. Here the mask is indicated by numeral 51b whilethe exposed reticle portion 51 is all that will pass light. The physicaldimensions of the exposed portion of the reticle 51 might be about inchin a horizontal direction and about inch in a vertical direction. It hasbeen found that this masked area of the reticle 51 will provide propervalidation where the lines in the bill and the reticle are within about5 to 7 percent of each other in number per inch, and will also allow forsome slight angular variation in the positioning of the bill in the trayso that the lines in the background of the portrait are not in exactalignment with the reticle 51. The angular misalignment of the reticlewith the lines in the bill results in the light-dark effect beingangularly misaligned, and this misalignment D cannot be too great or asubstantially complete darkening or blackout of the masked portion ofthe reticle will not occur. The results of the invention, as more fullydescribed below are dependent on achieving a full coverage of theunmasked area of the reticle, as seen in FIGURE 4, when the light-darkareas pass across.

If it were desired to measure the vertical lines in the portraitbackground the bill would have to move endwise relative to a reticleopening indicated by dotted lines 510 in FIGURE 4 and the lines in theopening 51c would be perpendicular to those in reticle 51. A cam actionat the end of tray insertion could deflect the tray for this endwisemovement to effect validation on the vertical lines. In some instancesit might be desirable to measure both horizontal and vertical lines fora dual validation.

In order to achieve a recognized signal with the lightdark effectillustrated in FIGURES 6a and 6b, it is contemplated that the light 55and photocell detection 53 will not be activated until the tray 12 isalmost fully to its inward position. In fact, it is anticipated that thecontacting of a microswich 90 will energize a sensing circuit 96 whichin turn actuates light 55 and photocell 53 to view the bill as it ismoved the last approximate A; of an inch of its inward movement until aplunger 80 operated by a solenoid 76 is actuated to hold the tray 12 inits inwardly position. It has been determined that during this finalmovement of the tray into position of about inch the light-dark areas 59as seen in FIGURE 6a and 6b alternately appear as light-dark to themasked area of the reticle many more times than necessary to assurevalidation. A sequence of light, dark, light, dark easily achieved inthe short space permitted for examination is sufficient to determinegenuineness. In any event, the alternation of the light-dark area 59 isindependent of the speed of the movement of the tray into the inwardlyposition. Thus, no costly constant speed drives, nor other synchronizingmechanism is necessary to achieve the desired creation within thereticle of the light-dark, as the mere manual positioning of the tray bythe operator will achieve the necessary relative movement to obtain adesired readout.

Readout is accomplished for validation by rather simplified logiccircuitry more fully illustrated in block diagram form in FIGURE 7.Particularly, the photocell pickup 53 gives a somewhat sinusoidal signal103 indicating the on-off viewing seen by the light passage through themasked reticle 51. Naturally, the on-off viewing need not be a uniformsine curve, but will show peaks and valleys independent of the rate ofmovement of the tray relative to the reticle. The signal 103 is thensent to a preamplifier 63 where the signal is amplified and looks inwaveform somewhat like the signal 105 indicated thereabove. The signal105 illustrates that four complete light viewings have been detected, asfour peaks are present. The preamplified signal is sent to a DC restorer65 where the sinusoidal portion of the signal 105 is separated andindicated in waveform by numeral 107. Conventional well known DCrestoration techniques may be utilized for this purpose. Such techniquesare well known to one skilled in the art. The signal 107 is sent to ashaper 67 where each of the peaks is represented as a large magnitudesmall duration pulse, as indicated in waveform by numeral 109. It shouldbe understood that the shaper 67 again is conventional circuitry wellknown in the art for changing the characteristics of voltage signals, asselectively desired.

The signal 109 represents four voltage pulses, or the viewing of fourlight-dark cycles completely by the reticle opening in the mask. Theprior signals 103 and 105 represent the passage of more than four areas,but for the purposes of the invention, it is believed that seeing onlytwo pulses or two areas will properly constitute a validation signal.Thus, although the shaper 67 may generate more than four pulses, thefirst four are the ones counted for validation although two wouldsuffice. It should be understood however, that although four pulses havebeen selected for validation on US. lower denomination bills, the

number of pulses counted for validation could vary as desired,

To logically count the number of pulses in signal 109, the inventioncontemplates suitable logic circuitry, which includes solid stateswitching devices, more commonly known as flip-flops. To this end, aflip-flop number 1 indicated by numeral 69 will count two pulses, one toswitch it one way and one back to its original position to then send thesignals on into a second flip-flop 71, which will count two more pulses.Thus when four pulses have been counted, a switch 73 will be actuated toindicate a validation signal 75 or to actuate the remainder of thesensing circuit for a light passage authentication as indicated inpatent application Ser. No. 405,666 identified above. If no validationsignal is received nothing occurs. After a predetermined period withouta validation signal the plunger is released causing the withdrawal ofthe tray, which in turn causes cancellation of any counts already made.Suitable solid state devices for the flip-flops 69 and 71 might beFairchild Fuh-92329, a medium power flip-flop adaptable for use incounters, which are made by the Fairchild Semi-conductor Company, 313Fairchild Drive, Mountainview, Calif.

It should be understood that the light-dark effect achieved by thereticle 51 will not achieve a complete elimination of light passage intothe photocell 53, but the features of the invention indicate that theamount of light reduction is highly significant, and in effect providesa second validation parameter. Specifically, with reference to FIGURE 8,typical light-dark signals for genuine, counterfeit and photocopy billsare indicated. It can be seen that each of the signals has a topmillivolt light level of about 75 mv. However, the big difference comesin the dark signal where the genuine bill has about 40 mv., While thecounterfeit has about 60 mv., and the photocopy about 70 mv. Thus, itbecomes quite clear that one can simply set thresholds on the darksignal that must be reached before genuineness can be indicated. In theillustration of FIGURE 8, this bottom threshold might be, for example,50 mv. In other words, the preamplifier 63 of the circuitry of FIGURE 7would not pick up and amplify any signals except those which came downto the predetermined minimum threshold level.

After a detailed and complete study of the printing technique used ongenuine currency and compared with that used on counterfeit andphotocopy bills, it was determined that the results of FIGURE 8 occurbecause of the properties of these printings and some special featuresof the apparatus of the invention. The printing of practically all theworlds paper currency is by the intaglio method which provides a widerange of tonal effects. However, because of the cost and complexity ofintaglio printing almost all attempts at counterfeiting have been by theletterpress or planographic processes. In the planographic process theprinting area is on the same level or plane as the non-printing area,while in the letterpress process, the ink printing area is in relief.Neither the letterpress nor planographic processes deposit as much inkand so cannot provide the deep tonal effects achieved by the release ofink from recessed wells below the surface of the plate in the intaglioprocess.

In order to take advantage of this printing distinction to achievesignals such as indicated in FIGURE 8, the invention contemplatesoperating the light source 55 at a low voltage level so that there willbe a high percentage of infra-red mixed with the white light. Thephotocell 53 is then selected to be more sensitive to infra-red and lowlight levels. For example, a Solar Energy Converter made by SolarSystems, Inc. of 8241 N. Kimball St., Skoki, Ill. meets the desiredobjects of the invention. Therefore, since the intaglio printing putsmore ink on the bill, this tends to absorb more infra-red radiation andconsequently the dark signal becomes much darker than is possible evenwith a very high resolution counterfeit bill made by planographic orletterpress processes.

Therefore, with the apparatus of the invention designed to simplymeasure the range or spread from voltage peak representing the lightsignal to voltage valley representing the dark signal set atpredetermined thresholds, the apparatus of the invention can therebyreadily distinguish between genuine currency and very high resolutioncounterfeit currency. The apparatus still looks for a predeterminednumber of light-dark areas, but the spread between light and dark mustmeet the threshold requirements.

As stated above, the width or height of the aperture in the direction ofbill movement defined by mask 51b will control the mask band to allowfor variation in the lines of the bill for shrinkage, age or otherpossible variations while the length of the aperture transverse to thedirection of bill movement will allow for angular variation between thelines in the bill and the reticle to a predetermined extent.

As pointed out above, the solenoid 76, controllable by a signal from apower supply 74 over a line 78, is adapted to position a plunger 80slida bly supported in the frame 11 to lock the slide 12 in the inposition. An extensible flat coil spring 82, having one end thereofsecured to the slide 12 and the coil portion thereof secured to theframe 11 functions to return the slide to the out position whensecondary validation or non-validation has been determined.

The control circuit power supply is conductively connected to a switch90 by means of a conductor 92. The switch 90, as pointed out above, isoperated by movement of the bill slide to the in position, and actuallyactuates the reticle validation circuitry about of an inch before thebill slide 12 is moved to the complete in position. Conductor means 94connects the power supply 74 with the secondary sensing circuit 96.Sensing circuit 96 is connected to a plurality of light sensitive cells42 and determines by a second test the validity of the bill 22. Anaccept signal is sent over a conductor 98 to actuate a motor 56 to drivea pair of rollers 91 and 93 thereby removing the bill from the chamber20. The full movement of the bill 22 from the chamber 20 causes theleading edge of the bill to actuate an arm 95 of a microswitch 97, whichin turn actuates a relay circuit 74 to effect a desired payout 77. Areject signal from the payout circuit deactuates solenoid 76 to releaseplunger 80 allowing withdrawal of the tray. The motor 56 is pivotallymounted by pin 57 so that a spring loaded screw 59 through the frame 11tends to bias the rollers 91 and 93 into resilient contact with eachother.

The accept or reject signal from the sensing circuit 96 may be dependentonly on the reticle line test or the voltage peak to voltage valleytest, as described above, or also on the light passage test described inthe aboveidentified patent application. The payout signal 77 mayenergize any suitable payout mechanism.

It is thus seen, that the essence of the invention is achieved byaccurately determining the number of lines in the portrait to backgroundsection of a bill by utilizing a reticle having substantially the samenumber of lines in parallel relation thereto so a moire effect createdthereby will set flip-flops, or other simple counting circuitry, with onand off signals. It should be understood, that suitable mechanicalmechanism could be included to move the tray 12 across the bill at theend of its movement after the reticle circuit has been energized to thusmeasure the vertical lines in the portrait background, rather than thehorizontal lines. In this instance, the reticle itself would have itslines in a vertical direction, and the mask would probably be turned 90from its illustrated position in FIGURE 4. Or a combination of tworeticles could be used to validate both horizontal and vertical lines.

What is claimed is:

1. An apparatus for authentication of paper securities havingrespectively uniform spaced lines on some portion thereof whichcomprises frame means defining a testing area,

first means movably mounted by the frame means to receive and hold asecurity to be validated, said first means being manually movablerelative to the testing area,

reticle means positioned in the testing area so as to be insubstantially parallel close spaced relation to the portion of thesecurity having the repetitively uniform lines when the first meanscarrying the paper security is moved manually relative to the testingarea, said reticle further having repetitively uniform spaced lines of anumber per inch substantially equal to the lines on the security andbeing in substantially parallel relation to the lines on the security tothereby create a high energy-low energy efiect with respect topredetermined radiant energy passing therethrough when the security ismanually moved in the testing area,

means to pass radiant energy through the portion of the security withthe repetitively uniform lines from the side thereof opposite thereticle,

radiant energy detection means to scan only a small selected portion ofthe reticle to determine the amount of radiant energy passed through thesecurity and the reticle as the security is moved by manual actuationrelative to the reticle, and

circuit means to count the number of low energy-high energy areaspassing the reticle upon the movement of the first means carrying thepaper security a predetermined distance relative to the reticle, and toprovide a validation signal if a predetermined minimum number of signalsare counted.

2. An apparatus according to claim 1 where the reticle is positionedwithin at least .025 inch spaced parallel relation to the security.

3. An apparatus according to claim 1 where the security is a monetarybill having a portrait thereon and the portion of the bill validated isthe parallel equally spaced lines in the background of the portrait.

4. An apparatus according to claim 1 where the selected area of thereticle viewed by the radiant energy detection means is masked to beabout V inch in the direction of security movement and about inchtransverse to the direction of security movement.

5. An apparatus according to claim 1 where the circuit means includes apreamplifier to receive and amplify the signal pulses from the radiantenergy detection means,

means to convert the amplified signal pulses into substantiallysinusoidal waveform pulses having peaks and valleys,

shaper means to convert each peak and valley of the square waveformpulse into a single, short, high amplitude signal, and

logic circuit means to count the number of high amplitude signals andindicate validation when a predetermined number of signals has beencounted.

6. An apparatus according to claim 1 where a second circuit means isactuated by the validation signal from the circuit means to provide asecond test in validation of the security.

7. An apparatus according to claim 1 where the means to pass radiantenergy through the security and the circuit means are only actuated forabout the final /1 travel of said means receiving the security as saidmeans are moved into the testing area, and Where the movement of saidmeans may be at any speed of relative movement to the reticle means toachieve validation.

8. An apparatus according to claim 1 where the circuit means detects thediiference between the amount of radiant energy passed through thenon-printed areas and the printed areas of the security and onlyindicating valid signals when the difference meets a predeterminedminimum value.

9. An apparatus according to claim 8 where the means to pass radiantenergy through a portion of the security emits substantially onlyinfra-red radiation, and the radiant energy detection means is highlysensitive to infra-red radiation.

10. An apparatus for authentication of paper securities having inkedlines on some portion thereof which comprises frame means defining atesting area, transport means carried by the frame means for movement toand from the testing area, said transport means adapted to carry asecurity to be validated,

reticle means carried by the frame means so as to be within the testingarea and in close spaced adjacent relation to a security carried by thetransport means, said reticle defining a complementary pattern to apattern carried by inked lines on a portion of the security,

means to pass radiated energy through the security and the reticleduring relative movement between the security and the reticle means,

means to detect the difference in the amount of radiated energy passedthrough the inked lines and the clear portions of the security, and topresent an electrical pulse Whenever this difference exceeds a minimumthreshold, and

means to count these electrical pulses and indicate validation when apredetermined minimum number of pulses have been counted.

References Cited WALTER STOLWEIN, Primary Examiner US. Cl. X.R.

